The Effect of Intraoperative Hyperoxemia on Postoperative Delirium in Geriatric Patients

The Effect of Intraoperative Hyperoxemia on Postoperative Delirium in Geriatric Patients and the Preventive Role of Oxygen Reserve Index"

Oxygen therapy is the most common treatment modality for patients with hypoxemia, but target values for normoxemia are not clearly defined. Therefore, iatrogenic hyperoxemia is a very common situation. Even though there are many side effects reported related to hyperoxemia and hyperoxemia is shown to be related to worse outcome than expected; clinicians still observe hyperoxemia frequently.

Oxygen reserve index (ORi™) (Masimo Corp., Irvine, USA) can guide clinicians in detection of hyperoxia. ORi is a parameter which can evaluate partial pressure of oxygen (PaO2) rating from 0 to 1. There are growing evidences in ORi that it might be helpful to reduce hyperoxia in general anesthesia. Continuous ORi monitoring can be used for detecting and preventing hyperoxia. The ability to perform FiO2 titration with ORi may be an appropriate monitoring management to prevent the harmful effects of hyperoxia.In this study, in patients who underwent major abdominal surgery; It was aimed to investigate the effectiveness of ORi-guided FiO2 titration in preventing hyperoxia.

Study Overview

• Status: Completed
• Conditions: Hyperoxia; Delirium in Old Age
• Intervention / Treatment: Procedure: control; Procedure: ORi+SpO2

Detailed Description

The definition of elderly by the World Health Organization is individuals aged 65 and older. As the average life expectancy continues to increase, the number of surgical procedures performed in the geriatric population is also increasing.

Postoperative delirium is a complication that occurs after surgery and is characterized by sudden-onset confusion, fluctuating mental status, and attention deficits. Its incidence increases in elderly patients and is higher in those with pre-existing mild cognitive impairment. The etiology encompasses multiple factors such as age, presence of additional comorbidities, metabolic disorders, hypoxia, polypharmacy, pain, hypothermia, and may be associated with the depth of anesthesia during surgery.

Early recognition and prevention of delirium will become more prominent in the future due to reduced hospitalization durations, postoperative complications, and mortality rates.

Various methods are available to detect hyperoxemia during surgery. Hyperoxemia can be detected using noninvasive finger pulse oximetry with the oxygen reserve index parameter. Oxygen levels can be noninvasively assessed during operations using routine oxygen saturation and oxygen reserve index measurements.

Delirium can be evaluated in both intensive care and ward patients. The gold standard for diagnosis is the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) criteria. DSM-5 criteria require psychiatric evaluation and are conducted by someone with psychiatric training. Additionally, the Confusion Assessment Method (CAM) is used for diagnosis and can be evaluated as CAM-ICU for intubated patients in intensive care units.

• Study Type: Observational
• Enrollment (Actual): 114

Contacts and Locations

Study Locations

• Turkey
  • İ̇zmi̇r, Turkey, 35640
    • Aykut Saritaş

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Older Adult
• Accepts Healthy Volunteers: Yes

• Sampling Method: Probability Sample

Study Population

Patients aged 65 and older. Geriatric patients

Description

Inclusion Criteria:

1. Patients aged 65 and older
2. Patients expected to have surgery lasting more than 2 hours
3. Patients with ASA (American Society of Anesthesiologists) classification 1-2-3-4
4. Patients planned to have at least 2 days of postoperative hospitalization

Exclusion Criteria:

1. Patients with preoperative central nervous system disorders or dementia
2. Patients with MMSE (Mini-Mental State Examination) scores of 23 or below
3. Patients unable to communicate
4. Emergency surgeries
5. Patients who refuse to participate in the study
6. Patients using high-dose vasopressors
7. Patients with peripheral hypoperfusion
8. Hemodynamically unstable patients

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Control group; In the control group, observation will be conducted solely by another anesthesia doctor or assistant participating in the study, and the data will be recorded blindly without being reported to the anesthesia doctor responsible for the surgery. The oxygen therapy administered by the anesthesia doctor in charge and the FiO2 values will be recorded independently and blindly, based solely on the clinician's own assessment, rather than according to the information obtained from ORi. Subsequently, for two days following the surgery, evaluations will be conducted twice daily at the same hours for ward patients using CAM, and for ICU patients using CAM-ICU. If delirium is detected, delirium subtyping will be performed using the Richmond Agitation-Sedation Scale (RASS).	Procedure: control; Fraction of inspired oxygen (FiO2) is titrated guided by oxygen saturation in that range; %95
ORi+SpO2 group; In the SpO2+ORi group; It is aimed to maintain SpO2 between %95 and %98, and ORi at 0.00. Data will be recorded every 10 minutes. After extubation, patients will first be evaluated in the postoperative recovery room. Subsequently, for two days following the surgery, evaluations will be conducted twice daily at the same hours for ward patients using CAM, and for ICU patients using CAM-ICU. If delirium is detected, delirium subtyping will be performed using the Richmond Agitation-Sedation Scale (RASS).	Procedure: ORi+SpO2; Titration of fraction of inspired oxygen (FiO2) guided by ORI and oxygen saturation FiO2 will be titrated by reducing 10% if Ori>0.01 and oxygen saturation ≥ 98% until Ori is 0.00. FiO2 will not be changed if Ori is 0.00 and %95

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Correlation of FiO2 and ORi value	Correlation of FiO2 value and ORi value. FiO2 adjusted until ORi reaches to zero and %95<oxygen saturation≤%98	Until the surgery is over
Correlation of ORi and Delirium	Correlation of ORİ and SpO2 values with delirium measured by CAM and CAM-ICU	Up to 48 hours

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Correlation of FiO2 and delirium	Correlation of FiO2 and delirium measured by CAM and CAM-ICU	first 10 th minutes after entubation and every 10 minutes until surgery is over

Collaborators and Investigators

• Sponsor: Tepecik Training and Research Hospital

Study record dates

Study Major Dates

• Study Start (Actual): October 1, 2023
• Primary Completion (Actual): July 5, 2024
• Study Completion (Actual): July 7, 2024

Study Registration Dates

• First Submitted: March 16, 2024
• First Submitted That Met QC Criteria: March 16, 2024
• First Posted (Actual): March 22, 2024

Study Record Updates

• Last Update Posted (Actual): July 9, 2024
• Last Update Submitted That Met QC Criteria: July 7, 2024
• Last Verified: March 1, 2024

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Mental Disorders; Pathologic Processes; Nervous System Diseases; Postoperative Complications; Neurologic Manifestations; Confusion; Neurobehavioral Manifestations; Neurocognitive Disorders; Signs and Symptoms, Respiratory; Delirium; Emergence Delirium; Hyperoxia
• Other Study ID Numbers: Delirium

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No